Homopolymers of alloocimene, a conjugated triene which is also classified as a tri-terpene, and copolymer of alloocimene with isobutylene is known in the art. The polymerization of conjugated trienes is quite complex considering that the monomer is a mixture of isomers and it can incorporate into the chain via numerous ways. In principle there are 12 different ways if the direction of growth is also taken into account. In addition, there is an increased potential for side reactions such as chain transfer to monomer or polymer, termination, back-biting reactions and grafting of the growing chain onto the already formed polymer. These side reactions can lead to branched structures and gel formation as well as loss of unsaturation. There are numerous articles and patents dealing with the polymerization of conjugated trienes. A comprehensive polymerization study of hexatriene, heptatriene and octatriene was carried out by Bell using anionic, cationic, emulsion and coordination polymerization systems1. R. Quick reported that the anionic homopolymerization of hexatriene and its block copolymerization with styrene resulted in branched and/or crosslinked products2. Veazey found that high molecular weight and high conjugated diene content polyalloocimene by anionic polymerization can only be obtained in polar solvents3. The cationic homopolymerization of alloocimene was studied by Marvel4,5 using Al(i-Bu)3/TiCl4, Al(i-Bu)3/VCl4, TiCl4, BF3(C2H6)2O and heptane or dichloromethane as solvent. He obtained amorphous soluble products with little or no cyclic structures and relatively high Tg (95-150° C.). He identified four possible main enchainment structures shown in Scheme 1. He found that about 35% of the alloocimene incorporated in 6-7 enchainment (I) and the rest in 4-7 enchainment (III) as shown in Scheme 1.
The carbocationic copolymerization of trienes with isobutylene was studied by Priola and his coworkers using EtAlCl2 and a 1/1 by volume mixture of heptane and methyl chloride as solvent6. Depending on the chemical structure of the triene, soluble or insoluble products were obtained. In case of alloocimene, chain transfer limited the reported viscosity average molecular weight (Mv=220,000 g/mol) in comparison with isobutylene homopolymerization (Mv>1 million g/mol) and only traces of conjugated unsaturation were found in the copolymer. No composition data was given.                1. Bell, V. L., J. Polymer Sci. Part A., 1964, 2(12), 5291-5303.        2. Quirk, R. P.; Rajeev, R., Rubber Chem. Tech., 1989, 62(2), 332-42.        3. Veazey, R. L., U.S. Pat. No. 4,694,059; 1987.        
The copolymerization of isobutylene (IB) with isoprene (IP) in methyl chloride (MeCI) using AlCl3 as a co-initiator with an initiator (water or CHI) is an important industrial process that produces butyl rubber. This is a slurry polymerization conducted at −90 to −100° C. where the polymer is in a glassy state, finely distributed in the reaction medium.1 IP acts as a strong chain transfer agent that reduces the molecular weight (MW) relative to IB homopolymerization.2 In the laboratory, the same system produces chunks of copolymer with lower MW, because the copolymerization is extremely fast and isothermal conditions cannot be achieved. For example, an IB-IP copolymer with Mn=125,000 g/mol and Mw=420,000 g/mol was produced in 47 sec with 86.7% conversion in the laboratory.3 It should also be noted that in the laboratory no water addition is necessary due to the presence of adventitious moisture. In contrast, the industrial process requires the addition of a cationogen such as water or HCI, due to the much smaller surface to volume ratio.                1. Puskas, J. E.; Kaszas, G. In Encyclopedia of Polymer Science and Technology; Mark, H. F., Ed.; Wiley-Interscience 2003, Vol. 5, pp 382-418.        2. Kennedy, J. P. Cationic Polymerization of Olefins: A Critical Inventory; Wiley-Interscience: New York, 1975.        3. Puskas, J. E.; Michel, A. J.; Brister, L. B. Kautsch. Gummi Kunstst. 2000, 53, 1-5.        
The present invention thus describes the production of copolymers comprising at least two cationically polymerizable monomers such as isobutylene and alloocimene and having a substantially inhomogeneous composition.